agree with jakeeeee,opera stands out when viewed in win8 since everything is flat and pointed.

it'd be nice to see opera button to be flat red as well (or at least make the gradient subtle) and Opera (text) and that half "O" beside it without drop-down shadow and (in my pov) make it a tad bigger so the borders around it would be small.

nevertheless, best theme!

edit:something like this<normal>http://img199.imageshack.us/img199/253/snap1e.png

<hovered and pressed>http://img547.imageshack.us/img547/1369/snap2pz.png

i don't know how to adjust the borders around it so it would look compact like the add tab [+] button and the tab beside it.

again, this is only my suggestion but you don't necessarily need to change it right on haha